An interesting property of ultraviolet radiation is its ability to stimulate the phosphors of certain reactive materials and substances so as to produce a visually striking effect through the fluorescence of the material or substance.
The existence of phosphors in certain gemstones (e.g. diamonds) has been known to jewelers and gemologists for many years. In the case of diamonds, phosphors may be present in the form of impurity atoms of nitrogen, hydrogen and boron. These phosphors are largely undetectable in natural light conditions. However, under ultraviolet light, the phosphors may fluoresce in shades of orange, blue, yellow or green. Fluorescence refers to the property of a substance to emit light through absorbed UV radiation, while exposed to the source of the UV radiation. The Gemological Institute of America has estimated that approximately 25% to 35% of diamonds have some degree of fluorescence. Diamonds containing phosphors in different concentrations may be virtually indistinguishable from each other in natural light, but become differentially fluoresced when exposed to ultraviolet radiation. The fluorescence appears as the emitting of lumens directly from the gemstone.
When present in strong concentrations, the presence of these phosphors has been associated with flawed or lower quality stones. Thus, fluorescence has been used as a grading and descriptive tool by jewelers and gemologists. Ultraviolet inspection lights are typically used under laboratory conditions where outside light is blocked out. Such ultraviolet lights are not used in the presence of customers or in a store setting with typically bright ambient lighting. Further, the perceived negative value of the fluorescent stones has meant that jewelers have sought to hide this feature from, or deemphasize it, to customers. Stones with Medium Blue or Strong Blue or Very Strong Blue fluorescence grades trade at very significant discounts. This effect has not been used in a display context where the phosphor containing properties of items were particularly highlighted or promoted.
A showcase is typically a glazed case or box, or cabinet for displaying and protecting items. It may be used in various contexts in a permanent or temporary installation to exhibit items (or a single item) in a particularly attractive or favorable aspect. Frequently, showcases are used to display items of a particular high value or rarity to enable the items to be examined more closely.
However, showcases have not historically been used to display the fluorescent properties of ultraviolet-reactive materials because it has been thought that such materials needed to be examined in extremely low light or preferably complete darkness in order for the ultraviolet radiation to have visible effect.
In applicant's patent application U.S. Ser. No. 15/636,878, options for new means of constructing or retrofitting showcases with combined white and UV light are provided (incorporated herein by reference). The applicant discovered that in fact ultraviolet radiation and white light can be used together without substantially compromising the ability to stimulate visible fluorescence of an ultraviolet-reactive item, allowing for a new experience for observers (e.g. prospective purchasers). Even in the presence of white light, the applicant discovered that the ultraviolet-reactive item can appear to spontaneously “pop” to the observer's attention.
However, showcases are a major investment item for store owners. Rather than replace such large items with new showcases having specialized lighting systems, many store owners would prefer to use existing showcases with existing lighting systems. Options should exist for providing substructures to insert into existing showcases to provide new and dramatic supplementary UV and white light display possibilities.